Floating roof for storage tanks



2 Sheets-Sheet l W. G. MCCULLAM FLOATING ROOF FOR STORAGE TANKS vOriginal Filed June 16, 1952 Feb. 23, 1937.

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Feb. 23, 1937. w. G. MCCULLAM FLOATING ROOF FOR STORAGE TANKS 2 Sheets-Sheet 2 Original Filed June 16, 1932 Fig. 9 is "Fig, 8.

`Patented Feb. 23, 1937 i FLOATING 12.00F FOR STORAGE ".llANKS William G. McCullam, Elizabeth, N. Ji, assigner to Standard Oil Develo poration of Delaware pment Company. a cor- Original application June 16, 1932, Serial No.

Divided and this application Novembei' 1, 1934, Serial No.` 750,990. In Canada January 16, 1933 4 Claims. (Cl. 22o-26) This invention relates .to improvements in roofs or decks for storage tanks, especially those used for volatile liquids such as low boiling petroleum oils (gasoline and the like). The invention is particularly adapted to the construction of floating roofs but some of the principles of design may be advantageously used in roofs which are secured in place.

A principal object of the invention is to provide a roof of light Weight, self-buoyant material, for

example, balsa wood or equivalent wood. The

roof is made up of laminations and is suitably oilwaterand iire-proofed as described herein.

Another object of-theinvention is to improve the fastening means used to hold the seal on the floating roof.

Another object of the invention is to provide means for securing a oating roof 4in an elevated position when it is desired to ix'spect or clean the tank below the roof level.

Further objects and advantages of the invention wilLwbe apparent from the following description read in connection with the accompanying drawings, in which Fig. 1 is a top plan view of a storage tank provided with a iioating roof made according to this invention.

Fig. 2 is an Venlarged vertical section on line 2-2 of Fig. 1.

Fig. 3 is asimilar view indicating alternative methods of 'securing the laminations on the roof together.

Figs. 4, 5 and 6 are plan views showing a preferred way of laying out sectionslfor the building up of the 'iioating roof.

Fig. 7 is a view similar to Fig. 2 showing an alternative method of' building up vthe laminated structure.

Fig. 8 is a vvertical section throughthe edge o f the roof showing the. sealing ringand the means for securing the ring to the roof.

a vertical section on line 9--9 of Fig. 10 is a view similar toFlg. 8 but indicating the connection oi'l the ring retaining means with a roller for guiding the up and down move- 'ment of the oating roof, and

- Fig. 11 is a section through the roof and the tank indicating the means for sustaining the roo! in an elevated position..

Referring iirst to Figs. 1 and 2, reference number I indicates the side wall of 'a storage tank,

for example, a tank such as is used for storingv gasoline. Av oating roof 2 is placed in thetank with the usual clearance between the roof and the wall. This clearance is closed by the sealing ring I4 hereinafter described. The roof has a manhead 3 of any suitable construction. In general the roof will be fiat, but other shapesv may be adopted. f z

I In accordance with thisfinvention the body of the roof is made up of laminations of material such 'as balsa Wood, which is light weight, selfbuoyant in gasoline, andaeasily treated so as to prevent'abscrption of gasoline. As shown in Fig. 2, three layers of balsa Wood 4, 5 and 6, areprovided, each layer being made of strips which are laid at an angle to the layer next beneath. 'I'he llayers are secured together byoil-prooi.' and water-proof marine glue or similar material. A supporting structure in the form-of battens I of White pine or. the like is provided. As shown in Fig. 1 these battens are arranged in the form of a grid beneath the laminations. Suitable cross `ioints are provided where the battensintersect.' The battens are securedto the bottom layer of the roof byaluminum nails8 or in any other suitable way.

In Fig. 3 additional means for securing the layers of balsa Wood or the like together are illustrated. For example. aluminum nails 8a may be driven at an angle from one vlayer into the'next adjacent, or hardwood dowel -strips 9 may be in- When large roofs are to be constructed it is necessary 'to build it up of sections of vlaminated wood. A desirable pattern for these sections is indicated respectively II, I2 and Il in Figs. 4, 5

and 6. For example. in a roof having a diameter of 59 2", it is desirable to provide 16 sections as in Figs. 4 and 8 each as in Figs. 5 and 6. A

'Ihe entire root is preferably painted with a phenol :formaldehyde coating or equivalent material so as to make the wood impervious to oill and water. Additional protection against absorption ofliquids mayfbe provided in the form of'thin metal sheets @aand 5a (Fig. 7) inserted between the laminations. It is desirable to fireprooi the roof by suitable means such as a thin metal cover- 6a with Joints crimped or welded.

The preferred type of sealing means lbetween the tank wall 'and the roof as shown in Figs. 8, 9 and 10,v is a ring I4 oi leather, rubber, or other resilient material such as is commonly used in seals of this type. The means provided by' the present invention are in the manner of securing the ring to the roof. For this purpose a clamp in general S-shape designated I5 is provided.` 'Ihe bottom tum of the clamp yhas teeth I6'j adapted to sink into the lower layer of the roof. The middle turn of the clamp runs parallel with the top of the roof and is embedded in suitable packing material I1 such as the material known as transite. The inner ends lla of ring I4 are brought together over the packing material. An aluminum plate I8 overlies the ends Ila. To secure the assembly together an aluminum wedge I9 is driven between the aluminum plate I8 and the upper portion of the S-shape clamp. This is recessed at 20 to receive the wedge. Y

In Fig. 10 a similar construction is shown but the S-shape clamp is modified so as to serve as a support for a roller 2|. This roller is adapted to run on guides as is usual in the construction of floating roofs. In this figure, 22 indicates the clamping means and 23 the extension comprising a bearing 24 in which the-shaft of the wheel turns. An aluminum wedge 2,5 is driven between the top of the roof and the bottom o! extension 23 to hold the wheel in proper position. In Eig. 11 means are shown for supporting the roof at a convenient height so that men may 'work beneath it to clean out the-tank. 'I'his means comprises V-shape supports 26 secured to the under surface of the roof. In the bottom of the tank are secured tressels 21 by means oi bolts fastened to the bottom of the tank. In the ordinary operation the roof will be turned so that the V-shape supports do not make contact with the tressels. However, when it is desired to clean out the tank the root is turned so that when it sinks with the and hold the roof at a convenient height.

The present invention provides a satisfactory roof of low cost which can be installed in tanks even of the largest size. The sectional construction makes fabrication in the eld easy. Although reference has been made to specific materials in the illustrative description given above, it will be understood that other woods, metals, and fabrics may be used. s

Various changes and alternative arrangements withdrawal of the liquid, the V- shape supports will rest on `top of the tressels,

may be made within the scope of the appended claims, in which it is my intention to claim all novelty inherent in the invention as broadly as the prior art permits.

This application is a division oi.' my prior application Serial No. 617,566, filed June 16, 1932.

I claim:

1.v A liquid storage tank, comprising a bottom and side wall, a oating roof adapted to normally rest upon liquid in the tank, and means for sustaining the roof spaced a predetermined distance above the bottom of the tank when empty, said means including a set of supports on the bottom of the tank and a set of supportscarried by the roof on its underside, the supports of one set being movable to operative position where they will engage the supports of the other set or to inoperative position where they will clear said supports of said other set.

2. Apparatus as claimed in claim 1, in which the set of movable supports is carriedby the roof on its underside. s

3. In a liquid stora'geltank having a bottom wall, a oating roof adapted to rest upon liquid in the tank, spaced brackets depending from the roof, and spaced supports projecting upwardly from the bottom wall in the same radial position as the brackets whereby the brackets 'and supports can be aligned upon rotary movement of the roof and will support the roof in spaced relation to the bottom wall when the tank is empty.

4. In aliquid storage tank having a bottom wall, a floating roofadapted to rest upon liquid in the tank, spaced V-shaped brackets depending from the roof with the base of the V secured to the roof, and spaced tressels projecting upwardly from the bottom vgall in the same radial position as the brackets whereby the brackets and tressels can be aligned upon rotary movement of the roof and will support the roof in spaced relation to the bottom'w'all when kthe tank is empty.

WILLIAM G. MCCULLAM. 

